You have asked a great question. And I have the answer – sort of…
Cracked teeth are a big nemesis of the dental profession. Cracked teeth can present in many different ways, with many different sets of symptoms, and many possible outcomes. We determine the best course of treatment based on your symptoms and condition, but the outcomes of that treatment are difficult to predict based on what the dental industry calls “Cracked Tooth Syndrome”. This is the “nickname” we have given to encompass all of the possible outcomes. It is not an official term, but every dentist knows what it means.
All teeth, especially back teeth, have natural anatomical grooves, cusps, and ridges. This anatomy is what allows the teeth to “jigsaw” together for chewing and function. However, this anatomy also predisposes the teeth to fracture, almost as if the grooves are perforation lines. When you have decay (a cavity) we cannot leave the decay, or the tooth will eventually have a much bigger problem. That may be a crown, a root canal treatment and a crown, or even loss of the tooth. So we place a restoration (a filling). That filling will in most cases serve you for years. But the tooth is now weaker than it was before the decay set in. So now the tooth is even more prone to fracture.
Most fractures occur due to the normal wear, tear, and stresses that we place on teeth in normal function. A healthy adult can place between 250 and 300 pounds per square inch on their back teeth during function. Parafunctional habits like grinding or clenching can increase that pressure up to 1000% ! Adding to those stresses is the fact that most of us at one time or another chew things we shouldn’t. Things like ice, popcorn old maids, corn nuts, roasted nuts, hard candy, or the accidental bone in a piece of meat. During the course of these functions, we create small surface craze lines in the enamel. These lines may never progress, and may never require any further treatment. But sometimes these craze lines can progress, much like a small chip or crack in your car windshield. Eventually, the fracture will progress to the point of symptoms or complete fracture. When this happens, you come see us at the dental office, and we determine the course of treatment best suited to your symptoms and your tooth.
Dr. Miller would love to be able to determine the severity of your fracture beyond a shadow of a doubt. But in most cases that is not possible. The only way to truly determine the extent of the fracture is to remove the tooth and examine it in a laboratory under light and magnification. Unfortunately, we cannot screw the tooth back in after that! So Dr. Miller will attempt to determine the severity based on your symptoms and testing.
Based on the severity of your symptoms, we will recommend to you that you have:
A filling. We call this a restoration. It most likely will be tooth-colored bonded composite, but may be a porcelain onlay or inlay.
A crown. This is the most likely treatment. This may be gold, porcelain over metal, or an all-ceramic crown. The purpose of the crown is to cover the tooth, cover the fracture, and hold the tooth together to resist further fracture due to stresses of function.
A Root Canal Treatment and a Crown. If your symptoms are of a certain level, it will tell us that the living part of the tooth (nerve, blood vessels, fibers) is irreversibly irritated or damaged, and will not heal without this treatment. Once most teeth have Root Canal Therapy, they will also require a crown to protect them through the future.
Extraction of the tooth. In cases of severe fracture, it may not be possible to treat the tooth with any reasonable chance of success, and removal of the tooth becomes your best option.
Dr. Miller will diagnose your condition, and make his recommendation based on each individual tooth. He will explain it clearly, and give you the chance to ask any questions that you may have.
Statistics that are available to us vary based on the individual studies, but generally are consistent:
20% of ALL teeth that have a crown placed, for any reason, will eventually need Root Canal Therapy. Add the presence of a crack or fracture, and that percentage goes up.
40-50% of cracked teeth will become stable after placement of the crown.
40-50% of cracked teeth will eventually need Root Canal Therapy, soon or in the future. Sometime this is apparent to us before the crown is placed. Sometimes it may not manifest for months or years.
5-7% of teeth with fractures will be lost at some point (extracted), even after any or all of the other treatments have been done.
So you can see why we consider cracked teeth a nemesis. We will do our best to give you the best outcome. But ultimately, your tooth and your “personal biology” will make the final determination . Your symptoms may resolve, may worsen, or may resolve and then return months or years in the future. Any or all of these conditions are consistent with the consequences of having a cracked tooth.
Hope that answers your question…Sort of!